ESP8266 Community Forum

- Sun Feb 28, 2016 5:36 pm #42069 Yo.

Im actually developing a similar system.

This relay works with 3.3v logic, as long as you power it with 5v, otherwise it won't switch the relays.

http://www.aliexpress.com/item/Free-Shi ... 10301.html

- Sun Feb 28, 2016 6:25 pm #42074

Yo.

Im actually developing a similar system.

This relay works with 3.3v logic, as long as you power it with 5v, otherwise it won't switch the relays.

http://www.aliexpress.com/item/Free-Shi ... 10301.html

How much does each relay draw from each pin of the ESP8266, assuming you power the relay board with a sufficient 5v source? Less than 12mA each? I assume so...

- Mon Feb 29, 2016 5:54 am #42103 None of those "Arduino ready" boards draw much current on the input: they just need a very small current to drive an optocoupler, or a transistor, or something similar.

- Tue Mar 01, 2016 12:03 pm #42174 have included a simple discrete circuit that I use to drive some hi-power fans,.. 12v @ 3Amps.... so plenty of drive for your pumps and solenoids....

The original circuit was designed to work from 5v logic,.. but to work from 3.3v just change the input divider resistor eg R6 (from 12k) to 1k would be fine,.... the circuit only has to see 0.6v at the base of the transistor,.. so easily turned on in a 50/50 divider ( formed by R6/R13 ),....

The feedback for the fan tacho is not required,.. in you app,.. so disregard.

regards

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